Responses of 'Wonderful' pomegranates to controlled atmospheres

We evaluated the efficacy of atmospheric modification in controlling decay and maintaining quality of 'Wonderful' pomegranates kept at 5degreesC, 7.5degreesC or 10degreesC during the 1997-8 season using air, 2kPa O-2, air + 10kPa CO2, and 2kPa O-2 + 10kPa CO2. During the 1998-9 season we tested the following atmospheres at 5degreesC and 7.5degreesC: air, 5kPa O-2, air + 10kPa CO2, air + 15kPa CO2,5kPa O-2 + 10kPa CO2, 5kPa O-2 + 15kPa CO2. We found that it is possible to store pomegranates at 7.5degreesC in 5 kPa O-2 + 15 kPa CO2 for up to 5 months, provided that the level of latent fungal infections at the time of harvest is low and that the pomegranates are sorted carefully after harvest to store only fruits that are free from defects and decay. CO2-enriched atmospheres resulted in higher concentrations of acetaldehyde, ethanol, and ethyl acetate, especially after 4 and 5 months of storage. Accumulation of these volatiles was greater at 7.5degreesC than at 5degreesC, but in both cases the highest concentrations were below the threshold values for detection of off-flavors.